V. V. Kuzmin - Post-graduate Student, Nizhniy Novgorod State Technical University n.a. R.E. Alekseev. E-mail: vvk1987@yandex.ru
D. V. Milov - Post-graduate Student, Nizhniy Novgorod State Technical University n.a. R.E. Alekseev. E-mail: milovdv@mail.ru